Thermoplastic elastomer compositions are versatile as they exhibit beneficial elastomeric properties and yet may be processed using standard thermoplastic processing equipment. Numerous different thermoplastic elastomer compositions, some with biorenewable components, have been proposed.
U.S. Patent Application Publication No. 2011/0184082 relates to a composition that includes a hydrogenated styrenic block copolymer that has at least one block A and at least one block B, and about 10 to about 90 percent by weight of an styrene-isobutylene-styrene block copolymer. Each A is an monoalkenyl arene and each B block is a controlled distribution copolymer of at least one mono alkenyl arene and at least one conjugated diene, having the general formula A-EB/A-A and (A-EB/A)nX. Each B block comprises terminal regions adjacent to the A blocks that are rich in conjugated diene units and one or more regions not adjacent to the A blocks that are rich in mono alkenyl arene units. Oil-free compositions that reportedly result in the combination of low gaseous permeability, low thermal conductivity, strong vibration and sound attenuation, and optionally high levels of light transmission with relatively low haze values while maintaining melt flow rates suitable for easy processibility are preferred.
U.S. Patent Application Publication No. 2010/00630008 relates to gelatinous elastomer compositions. In certain embodiments, a gelatinous elastomer composition is disclosed comprising about 1.0% to 50.0% block copolymer, about 0% to 98% mineral and/or synthetic oil, and about 0.0% to 98% triglyceride oil, about 0-15.0% free fatty acids, about 0-30% of a tack modification agent, about 0-20.0% of a biologically active agent and, optionally a phytosterol, ceramide and/or bisabolol. The gelatinous elastomer compositions are reportedly useful for applying a biologically active agent to a mammal. In certain embodiments, the gelatinous elastomer composition is formed into a molded article.
U.S. Patent Application Publication No. 2008/0171007 relates to a method of making up keratinous substrates involving applying onto the keratinous substrates a composition containing a) a block copolymer, b) a tackifier, c) a wax, d) a liquid fatty phase, e) a high viscosity ester, and f) optionally, a colorant.
U.S. Patent Application Publication No. 2008/0171006 relates to a method of making up keratinous substrates involving applying onto the keratinous substrate a composition containing a) a block copolymer, b) a tackifier, c) an alkyl silsesquioxane wax, d) a liquid fatty phase, and e) optionally, a colorant.
U.S. Patent Application Publication No. 2006/0121170 relates to a nonflowable gel composition including a vegetable oil and a thermoplastic elastomer. The nonflowable gel composition is characterized by its inability to flow when subjected to pressure. In another embodiment, the invention is a resilient gel composition which includes a vegetable oil and a thermoplastic elastomer. The resilient gel composition is characterized by its ability to recover its size and form following deformation. In another embodiment, a support surface for supporting the human body is disclosed, including the composition and a holding structure for holding the composition.
U.S. Pat. No. 7,884,158 relates to a cosmetic composition containing at least one block copolymer having a hard segment and a soft segment, at least one tackifier component, at least one phenylated silicone, at least one solvent, and optionally, at least one colorant.
U.S. Pat. No. 7,625,967 relates to oil gel compositions that include at least one non-aromatic ester oil and an anionic block copolymer of a mono alkenyl arene and a conjugated diene. The block copolymer is selectively hydrogenated and has mono alkenyl arene end blocks and a controlled distribution block of a mono alkenyl arene and a conjugated diene midblock. The ester oil is a non-aromatic, ester compound such as soybean oil, rapeseed oil, and other like compounds.
U.S. Pat. No. 7,267,855 relates to articles prepared from anionic block copolymers of mono alkenyl arenes and conjugated dienes, and to blends of such block copolymers with other polymers. The block copolymers are selectively hydrogenated and have mono alkenyl arene end blocks and controlled distribution blocks of mono alkenyl arenes and conjugated dienes. The block copolymer may be blended with at least one other polymer selected from the group consisting of olefin polymers, styrene polymers, amorphous resins and engineering thermoplastic resins.
U.S. Pat. No. 7,169,848 relates to a block copolymer containing a controlled distribution copolymer block of a conjugated diene and a mono alkenyl arene, where the controlled distribution copolymer block has terminal regions that are rich in conjugated diene units and a center region that is rich in mono alkenyl arene units. Also disclosed is a method for manufacture of the block copolymer.
U.S. Pat. No. 6,984,688 relates to a plasticized HSBC blended with polypropylene and free of a filler material which adversely affects clarity, provides an injection-moldable composition for an article required to have specific properties, namely, tensile strength in the range from about 4.13 to 8.96 MPa (600 to 1300 psi); tear strength in the range from about 21 to 52.6 N/mm (120 to 300 lbs/in); softness in the range from about 45 but less than 65 Shore A; and haze less than 20%, measured by ASTM D1003 using a BYK Gardner Micro Tri-gloss 4525 meter; and it is essential that all of these properties, along with the physical dimensions of the molded article, remain substantially unchanged after immersion of the article in boiling water for 1 hour. Such a composition reportedly may be injection molded to form a nipple for feeding an infant, or a teething ring, or goggles for a diver, and the articles are reportedly sterilizable and recyclable.
U.S. Pat. No. 6,673,857 relates to a thermoplastic elastomer composition comprising a) from 5 to 99% by weight of a block copolymer which is composed of hard blocks S made from vinyl aromatic monomers and of one or more random soft blocks B/S made from dienes and from vinyl aromatic monomers, b) from 1 to 95% by weight of a plasticizer with a higher polarity than white oil and with a lower polarity than diisooctyl phthalate, c) from 0 to 50% by weight of a polyolefin, and d) from 0 to 60% by weight of additives, where the total of a) to d) is 100% by weight. The use of the molding compositions to produce flexible or elastic moldings is described, as are the resultant moldings.
U.S. Pat. No. 6,031,053 relates to an elastomeric block copolymer comprising at least one block A having polymerized units of a vinylaromatic monomer and forming a rigid phase and at least one elastomeric block B/A having polymerized units of both vinylaromatic monomers and of a diene and forming a flexible phase, and glass transition temperature Tg of the block A being above 25° C. and that of the block B/A being below 25° C. and the phase volume ratio of block A to block B/A being chosen so that the amount of the rigid phase in the total block copolymer is 1 to 40% by volume and the amount of the diene is less than 50% by weight.
WO 2009/152870 relates to a group of thermoplastic elastomers reportedly with high environmental compatibility and biodegradability. The compositions include styrenic block copolymers, vegetal oils, solid vegetal oil products and at least one styrenic block copolymer modified with maleic anhydride, see claim 1.
WO 2008/087675 relates to a plastification process of thermoplastic elastomers derived from styrenic block copolymers, in which vegetal oils are used as plastifying substances, and thermoplastic elastomers obtained with the said process.
In view of the above it would be desirable to provide a high performance thermoplastic elastomer composition having biorenewable components, in particular at least a softener and/or at least one additional synergistic additive, preferably in a relatively high percentage by total weight in order to improve oil stability, and achieve desirable properties including low gloss, high physical strength, improved melt strength, and suitable melt viscosity range for both molding and extrusion. In reality, the solution is not simple as numerous issues exist that must be addressed, including, but not limited to, providing a relatively low hardness material without sacrificing tensile strength, recoverable high elongations, component compatibility, processibility, heat stability, weatherability, and substantially low or no softener or plasticizer bleed-out. Desirably, the properties should be met not only at the room temperature but from −30° C. to 135° C., more typically from −10° C. to 70° C., for about 168 hrs (1 week) for most of the applications. In spite of many disclosures reporting thermoplastic elastomer compositions including biorenewable content, the applicants have discovered oil bleed-out problems and poor heat resistance with many proposed formulations at various temperatures, which limit the commercialization and application of the bio-based thermoplastic elastomer compositions containing vegetable oils and the like.